The fire started shortly before 4 a.m. in a downstairs unit of the La Pacifica Apartments at 23394 Hemlock Ave., fire officials said.
Firefighters rescued one woman from the fire and found no other residents in the apartment. The woman was taken to an area hospital to be treated for smoke inhalation.
Five engine crews and 21 firefighters were sent to combat the blaze and extinguished the fire in under one hour.
Though the fire was contained to a single unit, two adjacent apartments suffered water damage. The cause of the fire was under investigation.
City News Service contributed to this report.